U.S. forces have been moved to the tiny Horn of Africa nation of Djibouti where defense officials say they could be used to attack al-Qaida terrorists inside Yemen.

Defense officials are trying to downplay the movement of some 800 Special Operations troops to Djibouti, along with the offshore deployment of the U.S. amphibious assault ship, the Belleau Wood, with its contingent of some two-thousand Marines.

The officials say that while the troops are poised for possible action, for the moment, they have no intelligence information on the whereabouts of al-Qaida terrorists that could trigger a U.S. operation. In that sense, they say much of what the force is doing is mere training.

The officials, speaking on condition of anonymity, also appear to link the lack of any military action to political sensitivities on the Yemeni side.

They say a small group of American military personnel is now in Yemen to discuss possible cooperation. The officials say any operations that are approved could feature Yemeni troops alone, U.S. and Yemeni troops acting together or operations strictly involving either U.S. Special Forces or even paramilitary forces controlled by the Central Intelligence Agency.

The Belleau Wood, which carries assault helicopters, could be used as a platform for such operations.

Yemen has long been a country of concern to the United States because of its links to terrorism. A U.S. destroyer, the USS Cole, was bombed in the port city of Aden two years ago during a refueling stop. Seventeen American sailors were killed.

Al-Qaida terrorists are also known to have taken shelter in a largely lawless area along the Yemeni border with Saudi Arabia.

Although the Pentagon has conducted a small training operation in Yemen, top defense officials say the country's cooperation in the war on terrorism is still at an early stage.

But Deputy Defense Secretary Paul Wolfowitz said in a recent interview the United States remains hopeful, as he put it, that the Yemenis "will become more energetic in pursuing some very dangerous people" who he said the United States knows are hiding in remote parts of the country.